1. Technical Field
The inventive concept relates to flash memory devices and methods of programming the same, and more particularly, to a flash memory device that compensates for a boosting charge effect (BCE) between memory cells without being affected by a change in a power voltage, and a programming method of the flash memory device.
2. Discussion of the Related Art
Flash memory is a device that maintains stored data without a power source. Flash memory is commonly used in portable electronics and removable storage devices, and to replace computer hard drives. Due to the scaling down of flash memory devices, gaps between the memory cells have shrunk, thereby increasing the impact of the BCE.
For example, in the case of adjacent memory cells on adjacent bit lines, where one cell (first cell) is to be programmed and the other cell (second cell) is not to be programmed, the BCE may cause the first cell to be over-programmed. This is so, because a voltage applied to the second cell to inhibit programming may be coupled to the first cell, and then, this extra voltage is added to a programming voltage applied to first cell. A conventional method of compensating for the BCE involves pre-setting the amount of coupling voltage applied to the first cell and reducing the program voltage by this amount. However, the pre-set amount varies when a power voltage supplied to the flash memory device is changed.
Accordingly, there is a need to reduce the effect of a change of a power voltage in a BCE compensation method.